Added another 16GB of RAM and now PC shuts down under heavy load. Help

Hello, I just added another 16GB of DDR4 3600CL16 to my custom-built system and PC started shutting down today when under heavy GPU load or both CPU/GPU load.
System specs
Windows 10 Version 21H2
Asus X570 TUF Wifi Plus motherboard
Ryzen 9 5900X processor
32GB DDR4 3600CL16 Crucial Ballistix BL2K8G36C16U4WL 4x8GB
EVGA 3080 FTW3
Fractal Design Ion+ 760P power supply
Plextor 256GB m.2 SSD OS drive
HP EX920 1TB m.2 SSD games
2 TB Samsung SATA SSD games
1TB HDD
6TB HDD
27" Asus Swift + 22" as my displays. It's a custom water-cooled build (built it myself) and I haven't had any issues with 32GB of ram before as last year I had a Ryzen 7 3700X and added the additional 16GB of ram and no issues.
I have tried the following:
updated bios and drivers, swapped the ram kits to the other slots. Left the new ram only in the recommended slots for single 2 dimm kit, replugged all PSU cables to the motherboard and GPU(not using any extensions or daisy chain)
I mine with my GPU and CPU when I'm not gaming and this hasn't been an issue but now with the two ram kits after a few minutes the PC shuts off, leaving only the motherboard and ram lights on, pressing the power button does nothing. The only way to get it started is cycling the power supply on/off switch. I gamed almost all day yesterday with no issues. The problem started this morning. The PC is plugged into a Cyberpower 1000PFCLCD backup UPS.

Bios settings are set to XMP, PBO enabled, no overclocking. I'm tech savvy with the hardware side of PC building but my software knowledge is weak, so I'm here seeking some help. Maybe I can provide some event viewer reports or something.

Thank you

Are all the 4 sticks same brand, same speed and same class?

Do you have a temperature monitor?
If you don't, I suggest open hardware monitor
Extract and run. very good.

Yes, same brand, same speed and timings. I have hwinfo and have the temps in tiles by my system tray. I just swapped the PSU with an old 850W I had and its working fine thus far. Will see if it shuts down again, if not then its the PSU.
Thanks